1. Technical Field
The present disclosure relates to a method for preparing nickel or palladium nanoparticles supported on a carbon support, which can be used as a catalyst or an electrode material of a fuel cell.
2. Description of Related Art
As a catalyst material, typically, a pure platinum, an alloy of platinum with other metals (e.g., palladium, nickel, and the like), or a surface alloy with a platinum layer formed thereon through heat treatment are used. However, as platinum is expensive and rare, researches have been actively carried out to provide platinum and/or other matal(s) having performance comparable to that of platinum in the form of nanoparticles having an increased surface area (see Stamenkovic, V. R. etc., Science, vol. 315, p. 493).
The so-called borohydride reduction method in which water or alcohol is used as a solvent and the so-called polyol method in which an alcohol solvent such as ethylene glycol or 1,2-propanediol is heated to induce dehydrogenation to reduce a metal precursor have been proposed to provide nanoparticles. These methods, however, have disadvantages. For example, nanoparticles tend to be agglomerated or are hardly formed on the surface of a carbon support. In addition, the metal precursor is not completely reduced or nanoparticles with high oxide content, which can decrease the catalytic activity, are formed.
Besides, other methods in which a solvent, a precursor, a reducing agent, etc. are used to support metal nanoparticles on carbon powder surface were proposed, as disclosed in Korean Patent Nos. 10-917697 and 10-738062, and Korean Patent Application Publication No. 10-2006-030591. They, however, are not suitable for large scale production because they require high-temperature heat treatment for reduction.
Accordingly, there is still a need for a new method for preparing nanoparticles.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.